1. Field of the Invention
The present invention relates generally to the field of analyte detection. More particularly, the present invention relates to the use of changes in the Whispering Gallery Mode (WGM) profiles of microspheroidal particles induced by the analyte binding to an immobilized binding partner on the particle to thereby detect the presence of the analyte. The present invention further relates to multiplexing protocols and to analytes detected by the WGM profile changes.
2. Description of the Prior Art
Bibliographic details of references provided in the subject specification are listed at the end of the specification.
Reference to any prior art in this specification is not, and should not be taken as, an acknowledgment or any form of suggestion that this prior art forms part of the common general knowledge in any country.
Rapid advances in genomics and proteomics has highlighted the inadequacies of traditional labor intensive methods for examining and detecting the interaction between two molecules. There is a necessity to devise extremely sensitive methods for the analysis of the interaction between different molecules and the detection of analytes in a sample. The development of methods which allow such analysis without the need to label one or other or both analytes and/or binding partners thereof, would be particularly desirable.
At present, gene-chips provide a means for high throughput nucleic acid analysis using oligonucleotide arrays immobilized to slides. However, this technology is dependent on the labeling of at least one of the molecules.
Attempts to develop methods and devices for examining the interaction of molecules which are not dependent on the labeling of one or more of the molecules include biosensors, which are most frequently used for examining DNA and/or proteins based on optical methods. See, for example, Baird and Myszka, J Mol Recognit 14:261-268, 2001, Rich and Myszka, J Mol Recognit 15:352-376, 2002, Li et al. Science 299:840-843, 2003 and Lin et al. Science 278:840-843, 1997 which describe optical methods including interferometric devices. Malmqvist, Nature 361:186-187, 1993 discloses surface plasmon resonance sensors (SPR). SPR detects a limit of <10 pg·mm−2 mass loading (Karlsson and Stahlberg, Anal Biochem 228:274-280, 1995) and allows real-time detection of biomolecular interactions. However, SPR requires specific and expensive instrumentation and the ability for multiplexed measurements is limited.
The present invention provides reagents and methods for, inter alia, the detection of interactions between analytes and their binding partners without need for labeling of either molecule.